Читать книгу Anterior Skull Base Tumors - Группа авторов - Страница 23

The histopathologic characteristics of these tumours vary according to the World Health Organisation (WHO) classification [1]. Nasopharyngeal carcinoma is classified into keratinising and non-keratinising phenotypes and corresponds to WHO type I and II/III grades [1]. Pathogenesis is strongly linked to Epstein-Barr virus (EBV) infection and has an ethnic and geographic distribution [7, 8]. Keratinising type (WHO I) is characterised by squamous differentiation showing keratinisation. Non-keratinising types (WHO II and III) are composed of sheets of undifferentiated malignant epithelial cells intimately intermingled with a chronic inflammatory infiltrate which is commonly EBV positive in endemic regions. In situ hybridisation for EBV-encoded RNA is routinely used to identify EBV uniformly in all tumour cells. Serology for EBV-encoded RNA is currently used for follow-up [9, 10].